Add newline aware output flag

1 files changed, 38 insertions, 16 deletions

diff --git a/hexv.c b/hexv.c
index ffde5f2..2e93a0f 100644
--- a/hexv.c
+++ b/hexv.c
@@ -1,8 +1,13 @@
+#include <fcntl.h>
+#include <unistd.h>
+#include <err.h>
+#include <errno.h>
+
 #include <stdlib.h>
+#include <string.h>
 #include <stdio.h>
 #include <stdint.h>
-#include <fcntl.h>
-#include <unistd.h>
+#include <stdbool.h>
 
 static const char hex[] = "0123456789abcdef";
 
@@ -20,6 +25,9 @@ static int gradient[256] = {
 	[255] = 255,
 };
 
+/* command-line arguments */
+static bool newline_aware = false;
+
 void
 colorhex(uint8_t c)
 {
@@ -69,39 +77,52 @@ printrow(char *row, size_t pos, size_t len)
 void
 tohex(int fd)
 {
-	size_t pos, i, k;
+	size_t last, pos, i, k;
 	ssize_t nread;
 	char buf[4096];
 	char row[16];
 
-	pos = 0;
+	last = pos = 0;
 	while (1) {
 		nread = read(fd, buf, sizeof(buf));
 		if (nread <= 0) break;
 
 		for (i = 0; i < nread; i++, pos++) {
-			row[pos % 16] = buf[i];
-			if ((pos + 1) % 16 == 0)
-				printrow(row, pos & ~15UL, 16);
+			row[pos - last] = buf[i];
+			if (pos == last + 15 || buf[i] == '\n' && newline_aware) {
+				printrow(row, last, pos - last + 1);
+				last = pos + 1;
+			}
 		}
 	}
 
-	if (pos % 16 != 0)
-		printrow(row, pos & ~15UL, pos % 16);
+	if (pos != last)
+		printrow(row, last, pos - last);
 }
 
 int
 main(int argc, const char **argv)
 {
-	int i, fd;
+	const char **arg, **farg;
+	int fd;
 
-	if (argc > 1) {
-		for (i = 1; i < argc; i++) {
-			if (i > 1) printf("\n");
-			fd = open(argv[i], O_RDONLY);
+	if (argc < 1) return 1;
+
+	for (arg = argv + 1; *arg; arg++) {
+		if (!strcmp(*arg, "-n") || !strcmp(*arg, "--newline-aware")) {
+			newline_aware = true;
+		} else {
+			break;
+		}
+	}
+
+	if (*arg) {
+		for (farg = arg; *farg; farg++) {
+			if (farg != arg) printf("\n");
+			fd = open(*farg, O_RDONLY);
 			if (fd < 0) {
-				fprintf(stderr, "Could not open file: %s\n",
-					argv[i]);
+				fprintf(stderr, "hexv: open '%s': %s",
+					*farg, strerror(errno));
 				continue;
 			}
 			tohex(fd);
@@ -111,3 +132,4 @@ main(int argc, const char **argv)
 		tohex(0);
 	}
 }
+